Go Back   EcoModder Forum > Off-Topic > The Lounge
Register Now
 Register Now
 


Reply  Post New Thread
 
Submit Tools LinkBack Thread Tools
Old 05-04-2012, 12:49 AM   #1 (permalink)
EcoModding Lurker
 
itsnotme1988's Avatar
 
Join Date: Aug 2008
Location: NC
Posts: 18

Saturn SL1 - '93 Saturn SL1
Last 3: 38.37 mpg (US)

Suzuki - '86 Suzuki Intruder VS750
90 day: 44.63 mpg (US)

Elantra GT - '05 Hyundai Elantra GT
90 day: 29.13 mpg (US)

Silverado HD - '11 Chevrolet 3500 HD
90 day: 11.87 mpg (US)

2008 Trailvoy - '08 Chevrolet Trailblazer LS
90 day: 14.96 mpg (US)

Ambie - '06 Ford Taurus SEL
90 day: 23.85 mpg (US)

Xj750j - '82 Yamaha Maxim XJ750
90 day: 32.47 mpg (US)
Thanks: 0
Thanked 0 Times in 0 Posts
How does propane burn hotter with fewer BTU than gas?

Had this conversation with my brother today and everything I have found shows I was wrong and propane has a higher flame temperature than gasoline. Came up because he was talking about sweepers in the warehouse where he works ran much hotter than if they were gas powered. How is this possible? From what I have found 1 gallon of gasoline has 125000BTU and 1 gallon of propane has 91700BTU.

__________________

  Reply With Quote
Alt Today
Popular topics

Other popular topics in this forum...

   
Old 05-04-2012, 01:00 AM   #2 (permalink)
EcoModding Apprentice
 
Join Date: Jan 2008
Location: SF Bay Area
Posts: 150

Silver Bullet - '02 VW Golf TDi
Thanks: 5
Thanked 16 Times in 11 Posts
Maybe it's because fuel in an ICE is metered by weight, not volume. Propane has about 22,000 btu/lb, whereas gasoline has about 17,5000 btu/lb. Or maybe it's because gasoline engines chill the incoming air charge through evaporative cooling, while propane is already vaporized before being mixed with the air.
__________________
Best tank ever: 72.1 mpg in February 2005, Seattle to S.F.
New personnal best 'all-city' tank June '08 ... 61.9 mpg!
Thanks to 'pulse-n-glide' technique.
  Reply With Quote
Old 05-04-2012, 01:10 AM   #3 (permalink)
Master EcoModder
 
skyking's Avatar
 
Join Date: Apr 2011
Location: Tacoma WA
Posts: 1,368

Woody - '96 Dodge Ram 2500 SLT
Team Cummins
90 day: 23.82 mpg (US)

Avion and Woody - '96 Dodge/Avion Ram 2500/5th wheel combo
90 day: 15.1 mpg (US)

TD eye eye eye - '03 Volkswagen Beetle GLS
90 day: 49.05 mpg (US)

Mule - '07 Dodge Ram 3500 ST
Thanks: 723
Thanked 503 Times in 328 Posts
as stated above, use weight instead of volume. The most convenient method for me is Gallon Gas Equivalent (GGE)
Gasoline gallon equivalent - Wikipedia, the free encyclopedia

Look how diesel shows up there, far above any other common fuel. It does indeed contribute to approximately 10% of the economy difference between a petrol and a diesel engine. The rest is due to the better efficiency of the diesel cycle.
__________________




2007 Dodge Ram 3500 SRW 4x4 with 6MT
2003 TDI Beetle
2002 TDI Beetle

currently parked - 1996 Dodge 2500 Cummins Turbodiesel
Custom cab, auto, 3.55 gears
  Reply With Quote
Old 05-04-2012, 10:08 AM   #4 (permalink)
This is the year
 
Join Date: Apr 2010
Location: Columbus, OH
Posts: 36

Bug - '06 Volkswagen Beetle TDI PKG1
90 day: 37.04 mpg (US)

F-350 - '11 Ford F-350 Lariat
90 day: 16.23 mpg (US)
Thanks: 1
Thanked 2 Times in 2 Posts
A bit technical, but the diesel cycle isn't more efficient than the otto cycle. Diesel engines are more efficient because of increased compression ratio's.
__________________



  Reply With Quote
Old 05-04-2012, 10:43 AM   #5 (permalink)
Master EcoModder
 
mechman600's Avatar
 
Join Date: Jul 2008
Location: Langley, BC
Posts: 1,226

Fusion - '16 Ford Fusion Hybrid SE
Thanks: 190
Thanked 272 Times in 166 Posts
Quote:
Originally Posted by big shafe View Post
A bit technical, but the diesel cycle isn't more efficient than the otto cycle. Diesel engines are more efficient because of increased compression ratio's.
+ less pumping losses because of no throttle plate
+ more energy content in fuel
  Reply With Quote
Old 05-04-2012, 10:50 AM   #6 (permalink)
This is the year
 
Join Date: Apr 2010
Location: Columbus, OH
Posts: 36

Bug - '06 Volkswagen Beetle TDI PKG1
90 day: 37.04 mpg (US)

F-350 - '11 Ford F-350 Lariat
90 day: 16.23 mpg (US)
Thanks: 1
Thanked 2 Times in 2 Posts
Compression ratio is the dominant factor for thermal efficiency, but those factors help.
__________________



  Reply With Quote
Old 05-04-2012, 10:54 AM   #7 (permalink)
EcoModding Apprentice
 
Join Date: Jan 2008
Location: SF Bay Area
Posts: 150

Silver Bullet - '02 VW Golf TDi
Thanks: 5
Thanked 16 Times in 11 Posts
There is a better explanation of diesel versus gasoline engines here.
__________________
Best tank ever: 72.1 mpg in February 2005, Seattle to S.F.
New personnal best 'all-city' tank June '08 ... 61.9 mpg!
Thanks to 'pulse-n-glide' technique.
  Reply With Quote
Old 05-04-2012, 01:49 PM   #8 (permalink)
Master EcoModder
 
Phantom's Avatar
 
Join Date: Jan 2010
Location: Independence, KY
Posts: 602

Blue Meanie - '02 Volkswagon Golf TDI
TEAM VW AUDI Group
90 day: 48.52 mpg (US)

Wife's car - '05 WV Passat TDI

Rudy - '94 Chevy C2500
Thanks: 89
Thanked 46 Times in 43 Posts
I think most of the reason is the air fuel ratio gasoline is 14.7lbs of air to 1lb of gas and propane is 15.67 to 1 so propane is burning one more pound of air.

__________________
I move at the speed of awesome.


"It's not rocket surgery!" -MetroMPG
  Reply With Quote
Reply  Post New Thread


Thread Tools




Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2021, vBulletin Solutions Inc.
Content Relevant URLs by vBSEO 3.5.2
All content copyright EcoModder.com